There is a growing interest in monitoring microplastics in the environment, corresponding to increased public concerns regarding their potential adverse effects on ecosystems. Monitoring microplastics in the environment is difficult due to the complex matrices that can prevent reliable analysis if samples are not properly prepared first. Unfortunately, sample preparation methods are not yet standardized, and the various efforts to validate them overlook key aspects. The goal of this study was to develop a sample preparation method for wastewater samples, which removes natural organic matter without altering the properties of microplastics. Three protocols, based on KOH, H2O2, and Fenton reactions, were chosen out of ten protocols after a literature review and pre-experiments. In order to investigate the effects of these reagents on seven polymers (PS, PE, PET, PP, PA, PVC, and PLA), this study employed µFTIR, laser diffraction-based particle size analysis, as well as TD-Pyr-GC/MS. Furthermore, the study discussed issues and inconsistencies with the Fenton reactions reported in the literature in previous validation efforts. The findings of this study suggest that both H2O2 and Fenton reactions are most effective in terms of organic matter removal from microplastic samples while not affecting the tested polymers, whereas KOH dissolved most PLA and PET particles.

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Different types of orthoses are available to clinicians for non-surgical treatment of acute ankle sprains. The goal of this study was to scientifically compare the movement restrictions in the sagittal and frontal plane during simulated walking between one adaptable semi-rigid brace (OrthoTri-Phase TM), four non-adaptable semi-rigid braces (OrthoStandard TM , MalleoLoc TM , MalleoSprint TM , VACOankle TM), and one rigid cast. Predefined time sequences of rotational moments and axial loading during gait were applied via an ankle joint simulator, with the pneumatic pressure inside the orthoses kept constant to ensure the same condition for different trials and orthoses. The peak ranges of motion (RoMs) in the frontal and sagittal plane during gait were analyzed for statistically significant differences using single-factorial ANOVA with post-hoc Bonferroni analysis. Significant differences in peak plantar-/dorsiflexion and in-/eversion RoM during gait were found between different types of orthoses. In the sagittal plane, the rigid cast most significantly restricted overall RoM followed by the Ortho Tri-Phase TM in Phase 1 and the Ortho Standard TM. The peak restriction in-/eversion RoM of the VACOankle TM came closest to the rigid cast, with a shift towards inversion. The VACOankle TM allowed for significantly larger dorsiflexion movement compared to all other orthoses. The present results may help clinicians in the decision-making process of finding the optimal orthosis for individual patients.